no one seems to do this themselves.... you need an experienced tech to do it as there are a lot of little things that need to be done right or they will make tons of noise.

As far as RPM in 5th its is 300-400 rpm if I remember correctly

 

$550 for 4.10 FRPP gears, install kit, labor and fluids. This was in Harrisburg, PA.

 

mine was about 500 forFRPP and labor, from a reputable shop that specializes in mustangs.

 

Gears, Labor, Royal Purple Fluids, Friction Modifier... in and out 1 hour and 45 minutes----- NO ISSUES....$395.00 Mustang Magic....

 

For those thinking of doing it yourself..... Let me say, from the experiance of someone who has done a ton of research on the topic, do NOT attempt this yourself if you have to ask how hard it is. Simply asking the question shows that you're not ready. This is because rear-end work is open-heart surgery. Yes, we can all swap a tranny in because its not open-heart surgery. Instead, its the whole heart being taken out and a new one put in. Now imagine if you opened up the tranny and tried to do work on the inside. Much different story!!!Its the same with rear-ends.... Opening that differential for anythingbesides just changing the fluid is a complex and highly dangerous operation.